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A guide to helping select the best energy efficiency compliance option.

Decisions, Decisions: Choosing the Best Multifamily NGBS Energy Efficiency Compliance Option

May 6, 2021
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There are many benefits to energy-efficient buildings. For multifamily buildings, these include lower operating costs for common areas, eligibility for preferred financing incentives, higher valuation on resale, greater marketability of the building to renters, lower utility bills, better quality, and increased comfort. When it comes to residential energy efficiency, there are basically two options for demonstrating energy compliance to the National Green Building Standard ICC-700 (NGBS): the Prescriptive and the Performance.

Multifamily developers interested in pursuing NGBS Green certification will often ask which energy compliance option is best. Below, I explain the two compliance options to help you decide which one is best for your next project.

NGBS Prescriptive Option:

The Prescriptive option is like a recipe. It provides the designer with a series of building component thresholds that must be met or exceeded to demonstrate compliance. Common prescriptive measures include minimum R-values for insulation or wall assemblies, acceptable infiltration rates, and efficiency requirements for mechanical systems, such as water heaters and HVAC equipment. The architect or builder designs the home to meet the Prescriptive option requirements and then an accredited NGBS Green Verifier must inspect the home to confirm compliance by verifying that the efficiency items on the list have been successfully included in the home.

When to Use:

The NGBS Prescriptive options include the following pathways:

PATH NGBS
2015
NGBS
2020 
Recom-
mended
for: 
Notes 
703 (Prescriptive Path)   Y  Y Bronze &
Silver 
Most affordable 
704 (Alternative Bronze -
ICC IECC or IRC Chapter 11) 
 N  Y Bronze COMcheck documentation needed
704 (Alternative Silver -
ICC IECC - Tropical)
 Y  Y Silver COMcheck documentation needed 

The 703 Prescriptive Path is the most affordable NGBS Prescriptive option because there is no mandatory COMcheck documentation, which can incur additional time and cost.

NGBS Performance Option:

The Performance option has fewer mandatory practices than the Prescriptive option. The Performance option allows a builder to make efficiency tradeoffs between components rather than having a fixed list of required components. Instead of a checklist of mandatory practices or systems, this option sets an efficiency baseline above the minimum building code. The Performance option supports creativity because it includes more design options. The builder demonstrates the home’s compliance by using energy modeling software to show that the annual energy performance is better than, or at least equal to, that of a building built using the prescriptive IECC or IRC code. The Performance option is the only way a home can earn the Emerald certification level.

When to Use:

The NGBS performance options include the following pathways:

PATH NGBS
2015
NGBS
2020 
Recom-
mended
for: 
Notes 
703 (Performance Path)   Y  Y Bronze
Silver
Gold &
Emerald 
Most affordable. Energy performance report needed. 
704 (HERS Index Target Path)   Y  N Bronze &
Silver
Confirmed HERS report needed.
704 (ERI Target Path)  N  Y Bronze
Silver
Gold &
Emerald
Affordable. Confirmed ERI report needed.
 701.1.4 (Alternative Bronze/Silver - ENERGY STAR  Y  Y Bronze &
Silver
Use only when also pursuing ENERGY STAR. ENERGY STAR certification and report needed.

The “Alternative Bronze/Silver” path should only be used when also pursuing ENERGY STAR, because additional reports and confirmed ratings might be needed, which can incur extra costs. Only the energy modeling report is needed for the 702-performance path.

The NGBS Green certification program provides builders with multiple energy paths for achieving energy compliance for their home’s certification.

Architects, developers, and building owners are encouraged to hire an accredited NGBS Green Verifier during the design stage to help pick the most cost-effect compliance path. Verifiers can be found on our Find a Verifier page. Project teams can download the free NGBS Green Scoring Tool to help them decide which compliance path is best for their particular project.

For more information or direction on which path best suits your project, please contact us.

** The NGBS 2020 Chapter 12 Certified Path energy compliance will covered in more detail in a future blog.

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